Performance Assessment of a Repository for Intermediate-Level Radioactive Waste Using the Probabilistic System Assessment Program Mascot

1994 ◽  
Vol 353 ◽  
Author(s):  
J. E. Sinclair ◽  
P.J. Agg

AbstractUK Nirex Ltd is planning the deep geological disposal of intermediate- and low-level radioactive wastes. A site close to Sellafield in Cumbria in the north-west of England has been selected for evaluation, and an extensive programme of site characterization is underway. In support of this programme of characterization, and in preparation for presentation of a post-closure radiological safety case, performance assessment using mathematical modelling has been carried out by the Disposal Safety Assessment Team at AEA Technology, on behalf of UK Nirex Ltd. This paper describes recent developments of the assessment models relating to the groundwater pathway for return of radionuclides to the environment.

1951 ◽  
Vol 31 (3-4) ◽  
pp. 132-148 ◽  
Author(s):  
K. M. Richardson ◽  
Alison Young

In 1946 a visit to the barrow, which lies on the edge of the western scarp of Chinnor Common, and a cursory examination of the adjoining area, cultivated during the war, resulted in finds of pottery and other objects indicating Iron Age occupation. The site lies on the saddleback of a Chiltern headland, at a height of about 800 ft. O.D. Two hollow ways traverse the western scarp, giving access to the area from the Upper Icknield Way, which contours the foot of the hill, then drops to cross the valley, passing some 600 yards to the north of the Iron Age site of Lodge Hill, Bledlow, and rising again continues northwards under Pulpit Hill camp and the Ellesborough Iron Age pits below Coombe Hill. The outlook across the Oxford plain to the west is extensive, embracing the hill-fort of Sinodun, clearly visible some fourteen miles distant on the farther bank of the Thames. The hollow way at the north-west end of the site leads down to a group of ‘rises’ hard by the remains of a Roman villa, and these springs are, at the present day, the nearest water-supply to the site.


2009 ◽  
Vol 33 (1) ◽  
pp. 93-107 ◽  
Author(s):  
Rolando Soler-Bientz ◽  
Simon Watson ◽  
David Infield

1957 ◽  
Vol 52 ◽  
pp. 195-196 ◽  
Author(s):  
A. J. B. Wace

Stamatakes's excavations in the Grave Circle area revealed, although it was not recognized until much later, that Mycenae had been inhabited in the Early Bronze Age, the Early Helladic Period. This was confirmed by subsequent researches which produced Early Helladic material from the foot of the Ramp, outside the Grave Circle, beneath the South House and below the Palace. Now the recent work of Dr. Papademetriou and ourselves has yielded fresh evidence. He has found more E.H. material in Schliemann's Grave Circle and some possible Neolithic sherds as well. In the area of the Prehistoric Cemetery outside the Cyclopean walls to the north-west of the Lion Gate we have found in a mixed unstratified layer at the eastern foot of the mound or tumulus which covered the dome of the ‘Tomb of Aegisthus’ many fragments of E.H. pottery, both decorated and plain. Since the plain E.H. ware found is of a simple, thickish fabric hand-polished and usually of a dull red or of a mud colour, we had at times wondered whether some of these fragments might not almost be classed as Neolithic. This was especially so in the case of some of the fragments from the lowest strata at the foot of the Ramp. Unfortunately these fragments were lost during the war in the Nauplia Museum and cannot now be checked.The discovery of Neolithic B pottery at the Argive Heraeum, and still more recently Dr. Caskey's most successful excavations at Lerna, encouraged us in the idea that a site like Mycenae was probably inhabited in Neolithic times also. Since the Early Helladic material is not stratified, except in areas like the foot of the Ramp or below the South House, it was hardly to be expected that Neolithic remains, if found, would be stratified. It is always possible, however, that some part of the site, not yet explored, may have escaped later disturbance or overbuilding. We have therefore now paid particular attention to the unstratified debris found above the Prehistoric Cemetery at the eastern foot of the Aegisthus mound. Among this we have found two sherds which are in our opinion almost certainly Neolithic.


1967 ◽  
Vol 1 (2) ◽  
pp. 38-39 ◽  
Author(s):  
J.P. Wild

The radio installations at Culgoora Observatory evolved from the work carried out at Dapto field station between 1952 and 1965—which in turn was based on earlier observations. The basic instrument at Dapto was a radiospectrograph which produced two solar spectra per second over a frequency range originally of 40-210 MHz and finally of 5-2000 MHz. Until 1957 the Dapto radio spectrograph was the only one operating in the world and it fell upon this instrument to reveal many of the spectral phenomena which are now well known. The spectrograph observations referred to the total flux from the Sun observations with high directivity began at Dapto in 1958 with the introduction of a swept-frequency interferometer which measured the one-dimensional (east-west) positions of bursts and their approximate angular size over a continuous range of frequencies between 40 and 70 MHz. The results obtained from this combination of spectrograph and interferometer indicated that great advances would be made in our knowledge and understanding of the phenomena if two-dimensional metre-wavelength pictures of the Sun could somehow be recorded at short time intervals of about Is—again in combination with spectrographic observations. This requirement led to the start of the radioheliograph project. One requirement for this instrument was a site with linear dimensions of the order of 3x3 km. This was far too large for the Dapto site and a new site was selected at Culgoora in the north-west plains of New South Wales. The virtues of this site are its size, flatness, freedom from flooding, low radio noise level and accessibility from Sydney by air transport. Its sunshine and optical-seeing properties also made it a highly desirable site for optical observations, and developments assumed a new significance when Dr. Giovanelli and his optical colleagues decided to join us at the same observatory.


1960 ◽  
Vol 80 ◽  
pp. 127-159 ◽  
Author(s):  
Hugh Plommer

The literature on the Acropolis seems to me as untidy as the site itself. Every discovery that could, on the present evidence, be made about its history, every truth that could be pertinently stated has already appeared, I should imagine, in one or other of the books or articles devoted to it since the Greek excavations of the eighties. I am merely attempting the humble but, I think, necessary task of sifting out what seem to me the more interesting discoveries, the more significant conclusions. Before we form any more theories, we must try to discover what under present circumstances we can reasonably know.In this paper I shall have space only to consider the history of the main buildings, one or perhaps two large temples and perhaps a large propylon, up to the Persian destruction of the archaic Acropolis in 480 and 479. The minor buildings of poros, with triglyphs barely 1 foot or 15 inches wide, and walls or columns consequently less than 15 feet high, will interest me only incidentally. I have found no clear evidence for the sites of any of these, not even Wiegand's ‘Building B’, considered by J. A. Bundgaard (pp. 55 ff.) to be the precursor of the north-west wing in the Periclean Propylaea. Moreover I can isolate the problem of the large buildings more conveniently and with a clearer conscience, because it has already been isolated by C. J. Herington in his stimulating book,Athena Parthenos and Athena Polias(Manchester, 1955). His thesis is an interesting one, that from far back in the archaic period two important temples stood on the Acropolis. The more southerly, dedicated to Athena the Warrior Maiden (Parthenos), occupied a site somewhere within the limits of the present Parthenon. The more northerly and the more important in state ritual was dedicated to Athena as the City Goddess, and occupied the site between the present Parthenon and Erechtheum, generally known as the ‘Doerpfeld Foundation’. Every visitor to Athens will know this series of old broken walls just south of the Caryatid Porch. Wiegand's is still, I think, the most workmanlike plan of it (Wiegand, figs. 72 and 117—my Fig. 1). Herington's thesis, then, enables me to arrange my questions as follows. How many successive temples occupied the Doerpfeld Foundation, what did they look like and how were they related to one another? And again, was there any important temple on the site of the present Parthenon before the decade 490–480, generally considered the date when a marble Parthenon was first attempted ? Because of its possible scale, I shall also have to consider the date and form of the archaic Propylon. If it were a large building, it could be the source of various large fragments hitherto assigned to temples; and Heberdey, the latest American books, and now Bundgaard all make it rather large, between 15 and 20 metres square. (For the actual dimensions they give, see below, pp. 146 ff.)


1895 ◽  
Vol 15 ◽  
pp. 93-99 ◽  
Author(s):  
W. Arkwright

The traveller riding westward from Macri soon reaches the Gargy Chai, which is the only perennial stream running into the Telmessian Gulf, and is rightly identified by Kiepert with the overflowing Glaucus. It rises in a ridge connecting the uplands of Kyzyl Kaya with the Aigür Dagh, a partly detached lower buttress standing out to the north-west of the long mountain commonly called Eljik Dagh in the maps, of which the eastern peak is named Chal Dagh, and the less lofty western peak Shimshir Dagh.Hence the stream runs to the S.S.E. down a deep glen, and after receiving the Nif Chai from the N.E., turns S.W. round the Kyzyl Dagh to the sea. Pliny, the only geographer who mentions the Glaucus, says that it had a tributary, the Telmedius. If, as the inhabitants positively assured me, the Nif Chai is merely a tributary of the other, it must be the Telmedius. If so, the name of Telandrus, which was on the Glaucus, must be given to the only ruins in the main valley, those at It-hissar, a site discovered by MM. Collignon and Duchesne, but not exactly described.


Author(s):  
Hitoshi Makino ◽  
Kazumasa Hioki ◽  
Hiroyuki Umeki ◽  
Hongzhi Yang ◽  
Hiroyasu Takase ◽  
...  

Comprehensive total system performance assessment (PA) is a key component of the safety case. Within this PA there are a number of tasks that reuse specific models and datasets, together with associated knowledge base for the disposal system considered. These are tasks where recent developments in the Knowledge Management System by Japan Atomic Energy Agency (JAEA KMS) can lead to optimisation of procedures. This paper will outline the reformulation of PA as a Knowledge Management (KM) task, discuss application of KM technologies to PA tasks, and illustrate how these can be handled electronically in a “Performance assessment All-In-one Report System (PAIRS)” utilising hyperlinks and embedded tools to minimise duplication of material, ease Quality Assurance (QA) and facilitate the regular updating required in the Japanese programme.


MRS Advances ◽  
2016 ◽  
Vol 1 (63-64) ◽  
pp. 4239-4245
Author(s):  
T. Goto ◽  
S. Mitsui ◽  
H. Takase ◽  
S. Kurosawa ◽  
M. Inagaki ◽  
...  

ABSTRACTNUMO and JAEA have been conducting a joint research since FY2011, which is aimed to enhance the methodology of repository design and performance assessment in preliminary investigation stage for the deep geological disposal of high-level radioactive waste. As a part of this joint research, we have been developing glass dissolution models which include various processes derived from glass-overpack-bentonite buffer interaction, considering the precipitation of Fe-silicates associated with steel overpack corrosion, and Si transport through altered layer of glass. The objective of this modeling work is to show comprehensively the lifetime of the vitrified waste due to glass matrix dissolution timescales through sensitivity analysis, and to identify the feature/process that most strongly influences the lifetime, and to identify future R&D issues that would help to improve the nuclide transport analysis with confidential value and the safety case in future. The sensitivity analysis suggested that the duration of the glass dissolution might be predicted in the ranges from 3.8×103 to 1.9×105 years. Also, the results indicated that the precipitation of Fe–silicate has the strongest influence on the long-team behavior of vitrified waste.


2005 ◽  
Vol 32 ◽  
pp. 155-165
Author(s):  
Ilze Biruta Loze

Miniature Neolithic figurines in clay are a special topic of research. This especially concerns areas where their representation has so far been poor. While carrying out archaeological excavations in Northern Kurzeme, the north-west coastal dune zone of Rīga Bay, a ritual-like complex was recovered at Ģipka A site belonging to the local Culture of Pit Ceramics. It consists of several large and smaller fireplaces and pits, with the finds of fragmentary clay figurines recovered under the palisade that surrounded the settlement. The head and body of the miniature anthropomorphic figurines in clay have original modelling. It is possible to single out two types of figurine: with rather broad cheekbones, and oval modelling of face. The large amount of ochre found in the settlement and the purposeful breaking of figurines are evidence of their role during a rite. Clay figurines have a symbolic meaning, and the signs depicted on them, incised walking stick-shape and other motifs, are the symbols of early farmers.


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